Abstract: The present invention relates to a method for forming insulating films on electromagnetic steel plates.Conventional films obtained by coating only an inorganic component such as a chromate, forming an organic-component film on an inorganic-component film or coating a mixture of both components individually have had disadvantages such as the occurrence of crateriform pinholes, reductions in punching properties, rises in the cost and decreases in interlayer resistance and the like.The present invention provides a method wherein a composition obtained by combining an acrylic resin and/or an acryl-styrene resin and guanamine resin as the organic components with an inorganic substance composed mainly of a chromate is coated and dried on an electromagnetic steel plate to form thereon an insulating film.According to the present invention, it is possible to form an insulating film which has excellent film properties and is free from said disadvantages.

Abstract: The present invention provides an insulating film-forming composition in which a mixed resinous liquid obtained from a specific proportion of an aqueous emulsion of an acrylic resin and/or an acryl-styrene base resin and an aqueous dispersion of PAN free substantially from any emulsifier/dispersant is added to and mixed with an inorganic film-forming composition containing as the main component a chromate or a chromate plus a phosphate, which has conventionally been used in the prior art, in a specific proportion, and a method for forming an insulating film by coating and drying such a composition on an electromagnetic steel plate. A substantial portion of the starting materials can be commerically available products. With the composition, provided to have a longer pot life, and method of the present invention, an efficient coating can be carried out, while suppressing foaming to a consideraly low level, thereby obtaining an insulating film excelling in insulating properties and other film properties.

Abstract: An aluminum coated steel sheet having excellent formability and corrosion resistance comprising a steel substrate of a recrystallized structure, an Al--Si coating layer of a recrystallized structure on at least one surface of the substrate, and a discontinuous intermediate layer of Al--Fe--Si intermetallic compounds. The product may be conveniently produced by rolling an Al--Si hot dipped steel sheet and annealing the rolled sheet under suitably selected conditions.

Abstract: A process for the partial hot dipping of a long steel strip is disclosed which comprises forming an oxidation-inhibiting film, oxygen-impermeable and thermally stable in a hot-dipping bath, which film is produced by the chemical reaction of an iron content in the steel strip with an oxidation inhibiting film-forming agent, such as an inorganic phosphoric acid compound, on a predetermined area of the steel strip surface, forming, as required, an intermediate layer comprising an inorganic binder, such as water glass, on the resulting film, forming a carbon-containing, plateing-stopping film as a top coat on the intermediate layer, and hot dipping the steel strip.